1. Field of the Invention
This invention relates to rotary devices with a cylinder barrel which can serve as a pump or as a motor. More particularly, the invention relates to such devices of the type which comprises a stator enclosing a rotor with a cylinder barrel and an oblique plate which acts, by means of spherical head and seating assemblies, on the outer ends of a plurality of cylindrical pistons partially engaged in cylinders which are formed in the cylinder barrel and the geometrical axes of which are regularly distributed over a surface of revolution coaxial with said cylinder barrel, the portion of each piston which is adjacent to the corresponding spherical head and seating assembly being rigidly connected to a rigid supporting element which slides axially against the internal face of an external skirt, which skirt is rigidly connected to the cylinder barrel for rotation therewith and surrounds all those portions of all the pistons which are outside the cylinders. Said surface of revolution is generally cylindrical but may also be conical.
2. Description of Prior Art
A pump of this type is described in U.S. Pat. No. 1,427,740 (Robert H. Johnson). In that pump, the oblique plate is rotary and carries seatings for spherical heads integral with the pistons. On each piston, the rigid supporting element, the purpose of which is not specified, is spaced axially apart from the center of the spherical head and it has an arched shape which ensures that it has a purely radial contact with the external skirt.